Headlights (Canada)

Exterior Lights

How the Circuit Works

Low Beams
The headlight relays receive battery voltage at all times. When the headlight switch is turned to the HEAD position with the dimmer switch in LOW, ground is applied through the BLU/RED wire to the coils of the headlight relays. The relays are then energized, applying battery voltage to the left and right headlights and the high beam indicator through fuses 15 and 17 (in the under-hood fuse/relay box). The low beam filaments come on because they are grounded through the normally closed contacts of the low beam cut relay and the dimmer switch.

High Beams
The headlight relays receive battery voltage at all times. When the headlight switch is turned to the HEAD position with the dimmer switch in HIGH, ground is applied through the BLU/RED wire to the coils of the headlight relays and the DRL control unit. The relays are then energized, applying battery voltage to the left and right headlights and the high beam indicator through fuses 15 and 17 (in the under-hood fuse/relay box). The high beam filaments and high beam indicator come on because the DRL control unit provides a path to ground through the RED/BLU (cavity 1) and the RED/BLK (cavity 11) wires. The low beam filaments remain off because the dimmer switch interrupts their ground path.

Flash-to-Pass
When the flash-to-pass switch is held in the ON position, ground is applied through the BLU/RED wire to the coils of the headlight relays and the DRL control unit. The relays are then energized, applying battery voltage to the left and right headlights and the high beam indicator through fuses 15 and 17 (in the under-hood fuse/relay box). The high beam filaments and high beam indicator come on because the DRL control unit provides a path to ground through the RED/BLU (cavity 1) and the RED/BLK (cavity 11) wires.

Daytime Running Lights
With the ignition switch in ON (II) and the parking brake released, the DRL control unit supplies a reduced voltage to the RED/YEL wire (cavity 10), about 12 volts to the RED/BLU wire (cavity 1), and ground to the RED/BLK wire (cavity 11). The DRL relay is then energized, providing a reduced voltage to both high beam filaments, causing them to come on at reduced brightness. At the same time, about 12 volts energize the coil of the low beam cut relay, removing the ground path from the low beam filaments. If the parking brake is applied, ground is provided to the DRL control unit through the GRN/ORN wire (cavity 6). If the parking brake is applied before the ignition switch is turned to ON (II), the daytime running lights mode will remain off until the parking brake is released. Once the high beams are in the daytime running lights mode, applying the parking brake will not turn them off. With the headlight switch moved from the OFF position or with the flash-to-pass switch in the ON position, ground is provided to the DRL control unit through the BLU/RED wire (cavity 8), and the control unit then turns off the daytime running lights.